Taking time out to help: would you help out a stranger?

Over the weekend, driving through a busy part of Perth with the tribe, we had a near miss (in the mining industry, where I work as a scientist, that's what we call it when an accident almost happens) with an elderly man who wandered out into the middle of the road.
Luckily (for all of us) I was driving well below the speed limit, so I could stop the car safely to let him cross the road. It was then that I noticed a lady on the other side of the road, struggling to carry a printer, paper, and various IT paraphernalia. She was waved to the man, then caught my eye and mouthed 'sorry'. The elderly man crossed the road safely. Just as the lady got to the edge of the road she stumbled and dropped everything at the edge of the road.
The car behind me roared around, clearly impatient at the hold up.
I had a choice to make. Should I do the same? Or should I help? How could I help when I was travelling alone with three little kids?
I choose to stick around, I was not in a rush, and even thought I didn't know the lady or the man (daughter and son? friends?), they both looked like they were having a tough time. I thought about it, then decided I could help without putting myself or the kids in the line of fire (more mining talk for placing yourself in a hazardous situation). Putting my hazard lights on to warn cars behind me that I had stopped, I waved to the lady to let her know I was stopping. There were two lanes so I figured they could go around. I sat waiting for several minutes until the lady had retrieved her printer, made sure the elderly man was ok and off the road.
Then we drove off. I thought about it, and realised that by taking the time to stop and wait we may have averted something nastier than a near miss. And really, what was the cost to me? A few extra minutes added to my trip? Nothing really in the grand scheme of things.
Have you helped someone out lately?
Enjoy xx